Didymo Algae likely to have huge impact on Aquaculture

ASHBURTON - Farmers and irrigation scheme operators could be in for a major increase in their workload if the rapidly spreading algae, didymo, hits Ashburton waterways.

For the manager of Ashburton’s Rangitata Diversion Race, John Young, the arrival of the algae is being treated as a ‘when, rather than if’ event.

“We’re quite concerned about the significant impact on our operation. If we get this, the biomass in our system will clog up the grills and they’ll need to be cleaned two or three times a day,” Mr Young said.

The velocity and depth of the RDR would provide an excellent breeding ground for the algae, he said.

With didymo now found in Takaka and spreading in the Waitaki area, its arrival in Ashburton’s rivers was just a matter of time, Mr Young said.

“There’s nothing we can do to prevent this, no silver bullet to deal with it. We just have to look at how we will manage it.” With one third of the RDR’s users spray irrigators using water stored in pond systems, the impact of didymo on farming operations could be significant, Mr Young said.